skylogger
Posts: 61
Joined: Sun Dec 14, 2014 3:54 am

Re: Troubleshooting and repair for On-board Charger (OBC), DC-DC Converter

Wed Sep 19, 2018 8:04 pm

Quix: It sounds like the dealar has changed out the fuse but it may have blown again since they did not fix what causes the fuse to blow.
You cannot just look at the fuse to see if it's blown, because the fuse is filled with sand. You have to use an ohm meter and check for close to zero ohms for a good fuse. Make sure car is shut down so no voltage is running through the fuse when testing.
The Dealership price of a fuse here in Australia is $AU25, so your $US100 Price probably included the labour cost to fit it.

electronpusher
Posts: 43
Joined: Sun Jun 25, 2017 3:11 am

Re: Troubleshooting and repair for On-board Charger (OBC), DC-DC Converter

Thu Sep 20, 2018 9:24 pm

coulomb wrote:

Electrically, yes it would work, and it seems to have very roughly similar "speed" (it's hard to tell, because the original fuse has very wide times for blowing at a particular current).

But you'd want the "bolted contacts" version of that fuse, which unfortunately none of the regular parts suppliers seems to stock. Even if you found that, the bolts are 45 mm apart, and the holes in these would be 50.6 mm apart. So you'd have to enlarge the slots.

The best I came up with is in this post. It's also a photovoltaic 38x10 mm fuse (the original is a non-standard 31x7.2 mm), but with the bolted contacts, and the holes are 51 mm apart. So again, you'd need to enlarge the slots. The Australian version of the Mouser URL for this part is https://au.mouser.com/ProductDetail/Bus ... YZ2445BpOV . It's almost expensive enough to get free shipping; add something inexpensive to the order to qualify for free shipping (AU$45 minimum order). Something I ordered recently from Mouser took 6 calendar days to arrive (to an Eastern capital city address).


Thanks coulomb, just want to source some alternative fuses if the OEM become difficult to obtain. Work on ours starts tomorrow.

electronpusher
Posts: 43
Joined: Sun Jun 25, 2017 3:11 am

Re: Troubleshooting and repair for On-board Charger (OBC), DC-DC Converter

Thu Sep 20, 2018 9:27 pm

skylogger wrote:Electronpusher: When I ran into problems getting the original 20 amp fuse, I bought the 10x38 fuse type that you showed in your last post.
To be able to use it, I also bought a DIN fuse holder, and ran wires from the fuse holder with small ring terminals that would screw down to the original two screw terminals that the tabs on the original fuse mounted to. You posted link to RS. you might check if RS sell 10x38 fuse holders like this:
https://au.rs-online.com/web/p/rail-mou ... s/7686134/


Thanks skylogger, I might get a couple of those, at lest I can test while waiting for the OEM fuse.

electronpusher
Posts: 43
Joined: Sun Jun 25, 2017 3:11 am

Re: Troubleshooting and repair for On-board Charger (OBC), DC-DC Converter

Thu Sep 20, 2018 9:37 pm

So with these non OEM fuses, does anyone think it would be doable to convert the fuses without screw terminals into fuses with screw terminals by soldering the fuse to some copper fashioned into screw terminals and soldering the fuse to the copper?

coulomb
Posts: 100
Joined: Sun Jun 10, 2018 8:32 pm
Location: Brisbane, Australia

Re: Troubleshooting and repair for On-board Charger (OBC), DC-DC Converter

Fri Sep 21, 2018 4:11 am

electronpusher wrote:So with these non OEM fuses, does anyone think it would be doable to convert the fuses without screw terminals into fuses with screw terminals by soldering the fuse to some copper fashioned into screw terminals and soldering the fuse to the copper?

I doubt it. Fuses are inherently thermal in nature; soldering those big end caps requires a lot of heat. I think you'd destroy the fuse; I've destroyed several trying to do just that. But they were 3AB (same size as 3AG but ceramic). Those fuses all ended up high resistance or open circuit. A 10x38 mm fuse is a bit bigger, so it might work, but it's a big gamble. They're expensive enough (to me) that you likely wouldn't want to buy a few spares and experiment.

Hacking the Mouser fuse, which already has bolt-on connections, is a different matter. You can reshape the tags without heating up the fuse proper to any great degree.

If you're set on using the 10x38 mm fuse without the bolt-on tags, you might be able to find smaller, cheaper, non-DIN rail mount fuse holders that should be easier to find space for. Edit: such as this one.

Image

Or you could solder or screw to these sorts of clips, but it would be awkward making it safe and reasonably vibration-proof.

Image

electronpusher
Posts: 43
Joined: Sun Jun 25, 2017 3:11 am

Re: Troubleshooting and repair for On-board Charger (OBC), DC-DC Converter

Fri Sep 21, 2018 6:10 pm

Thanks for the explanation @coulomb. Makes sense.

electronpusher
Posts: 43
Joined: Sun Jun 25, 2017 3:11 am

Re: Troubleshooting and repair for On-board Charger (OBC), DC-DC Converter

Sat Sep 22, 2018 9:43 pm

Hi All

Open heart surgery on our iMiEV has begun. I have opened up the OBC, removed the top board, and removed all the screws that I know of that hold the middle board (with the blown caps) from the OBC, but it will not budge (with light force), and I am too afraid to apply too much force, because I assume there is something else holding this down.

So, how do I remove the middle board? Is there screws in the underside? Is it because of the waffle plate, and therefore takes a little force. Do I need to rub my tummy, tap my head while standing on one foot to pull it out.

Thanks for your help.

ImageImage
Last edited by electronpusher on Sat Sep 22, 2018 11:41 pm, edited 1 time in total.

skylogger
Posts: 61
Joined: Sun Dec 14, 2014 3:54 am

Re: Troubleshooting and repair for On-board Charger (OBC), DC-DC Converter

Sat Sep 22, 2018 10:12 pm

Hi Electronpusher: From the photo you just posted, it looks like you have all the screws removed, but have not unscrewed/removed the four hex standoffs. Even though it looks like the standoffs do not make contact to the PCB, They actually mount the heat sink to the box below, and since the PCB is still soldered to the waffle plate, the whole thing will be tied down to the box until you undo and remove the four hex standoffs. Note, Looks like you have removed the central one. Once you have removed the standoffs, you will still need to apply some gentle pressure with a screwdriver between the edge of the box and the waffle plate, to break the heat sink compound seal. Then it should come out pretty easily.

electronpusher
Posts: 43
Joined: Sun Jun 25, 2017 3:11 am

Re: Troubleshooting and repair for On-board Charger (OBC), DC-DC Converter

Sat Sep 22, 2018 10:19 pm

Thanks @skylogger, I'll give it a go now.

electronpusher
Posts: 43
Joined: Sun Jun 25, 2017 3:11 am

Re: Troubleshooting and repair for On-board Charger (OBC), DC-DC Converter

Sat Sep 22, 2018 10:45 pm

Once I removed those spacers, the board came out really easy. Did not appear to be much heat transfer compound on the bottom of the waffle plate. Any recommendations for replacement paste, or will any old heat transfer compound to?

So now I am going to be removing the black potting from around the riser, anything I should be careful of under the black potting?

I am using these to remove the potting since I figure they will be gentle on any tracers underneath.

https://www.priceline.com.au/manicare-cuticle-sticks-1-ea

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